A runway is a long path for planes to take off and land on an airport.
You might hear the word "runway" mentioned when talking about flights or airports. It's used to describe the way a plane moves, especially at takeoff or landing. Imagine you're watching airplanes arrive at a busy airport - you'll see them taxi down a long path that leads to the end of the runway, where they then lift off into the air. Runways can also be paved with special material to help planes slow down when they land.
How common is "runway"?
Word runway is considered uncommon in modern English. It has a balanced usage among all categories: speech, fiction, newspapers and academic texts.
Definitions
noun
A defined, narrow section of land or an artificial structure used for access.
The usual path taken by deer or other wild animals, such as from a forest to a water source.
A narrow walkway (often on a platform) extending from a stage on which people walk, especially one used by models during fashion shows.
In javelin, long jump, and similar events: a short track along which athletes can accelerate themselves for their jumps or throws.
A section of land, usually paved, for airplanes to land on or take off from.
Hence, the number of months that a startup company can operate on its cash reserves.